Sulphides of dialkyl phenols



Patented ar. 6, i945 OFFlCE 111" OF DIALKYL PHENOLS Robert L. Sibley, Nitro, W. Va, assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application June 9, 1942, Serial No. 446,381

4 Claims.

The present invention relates to a new class of chemical compounds. More particularly, the present invention relates to a new class of phenolic sulphides. The new compounds are useful as oxidation inhibitors and are especially useful in rubber and mineral oils.

The new compounds are the sulphides of didroxy group, undergo reaction with sulphur halides to form phenolic sulphides in which a sulphur atom is attached t a ring carbon atom. While some substituted phenols undergo a similar reaction, in general, they give uncertain results and many have been reported as inactive. However, it has been found in accordance with the present invention that monohydric phenols unsubstituted in the 2 and 6 positions but containing two allgvl groups at least one of which contains a. plurality of carbon atoms react with sulphur halides to produce valuable products. After reacting or attempting to react a large number of substituted phenols, it has been concluded that other groups must be absent. Phenols containing additional alkyl groups or different substituting groups either failed to react or produced inferior products.

The new compounds can be prepared most easily and cheaply, it is believed, by the action of sulphur monochloride (S2C12) or sulphur dichloride ($012) on the dialkyl phenol. However,

where convenient or desirable other methods of synthesis may be used. Other sulphur halides as for example sulphur bromide may be substituted for the sulphur chloride. It may be pointed out that since more than one position is available at which the's'ulphur may attach to the'ring, more than a single reaction product may be formed and itis within the purview of this invention to prepare the composite reaction products which may then be used directly as oxidation intiary butyl phenyl) monosulphide and disulphide, di(l-hydroxy 3-methyl 4 isopropyl phenyl) monosulphide and disulphide, di(1-hydroxy3-methyl 4 tertiary amyl phenyl) monosulphide and disulphide, di(l-hydroxy 3-tertiary butyl 4-methyl phenyl) monosulphide and disulphide, di(l-hy droxy 3-isopropyl 4-methyl phenyl) monosulphide and disulphide, di(l-hydroxy 3-methyl 4- secondary butyl phenyl) monosulphide and disulphide, di(l-hydroxy 3-methyl 4-isoamyl phenyl) monosulphide and disulphide, di(l-hydroxy 3,5- ditertiary butyl phenyl) mqnosulphideand disulphide, di(l-hydroxy 3,5-ditertiary amyl phenyl) monosulphide and disulphide, di(l-hydroxy 3- methyl 5-isopropyl phenyl) monosulphide and disulphide, di(l-hydro'xy 3-methyl S-tertiary butyl phenyl) monosulphide anddisulphide and di(l-hydroxy 3-methy1 fi-t'ertiary amyl monosulphide and disulphide.

The following is a specific example of the invention illustrative thereof but not limitative of the invention.

Example Substantially 55 parts of 4 tertiary butyl meta cresol was dissolved in substantially 375 parts by weight of carbon tetrachloride. A solution of substantially 19 parts by weight of SC12 in substantially 150 parts by weight of carbon tetrachloride was slowly added to the solution of the dialkyl 5 C. and filtered A white crystalline product believed to be di(1-hydrox y'3-methy1 butyl phenyl) monosulphide,

was obtained, M. P. 15'7-158v C.

Another preparation similar to the above was carried out except that instead of cooling and illtering at the end of the reaction the solvent was removed by evaporation. In this manner a pale amber colored resin melting below 100 C. was

4-tertiary C(CHaM obtained. As an age resistor for rubber this resin was only slightlyinfe'rior to the crystalline product mentioned above.

phenyl) .This invention is notlimited to the specific where It represents a tertiary alkyl group concompounds mentioned above nor to the particular taming less than six carbon atom process described. For example other solvents 3. A monosulphide oi 3-methyi 4-tertiary butyl may be used and other means of eflecting reacphenol hevine the formula tion. The present invention is limited solely by 5 on o the claims attached hereto as part of the present invention. s

What is claimed is: V cm CH 1. A monosulphideot a 3 methyl 4 alkyl monohydric phenol having the formula 10 on? our on OK HI H: 4. A monos phide of a 3,4 dialkyl monohydric' Cm phenol having formula on on I. R I

where R represents an alkyl group containing more than two but less than six carbon atoms. 7

2. A monosulphide of a 3 methyl 4 alkyl mono- 0 hydric phenol having the formula R x R on OH where R, represents an alkyl group containing more than two but less than six carbon atoms and R is a short chain alkyl group. CH3 25 7 ROBERT L. SIBLEY. 

